Carbon for incandescent lamps



(No Model.)

0. J. VAN DEPOELE.

CARBON FOR INGANDESGENT LAMPS.

No. 337,899. Patented Mar. 16, 1886.

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UNITED STATES ATENT i -Fries.

CARBON FOR INCA NDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 337,899, dated March 16,1886.

Application filed August 7, 1885.

To all whom it may concern:

Be it known that I, CHARLES J. VAN DE- POELE, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Carbons for Incandescent Lamps, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to certain new and useful improvements in carbons for incandescent lamps; and the invention consists in the peculiar construction of the carbon, as hereinafter more fully described, and then specifically pointed out by the claim.

In the accompanying drawings, which form a part of this specification, Figure l is a sectional elevation showing the plug, the connectjug-wires, the carbons, the manner of connecting the same to the wires, and the matrix in which the carbonization takes place. Fig. 2 is a plan of the carbonizing furnace or oven. Fig. 3 is a vertical section of the same, showing the manner of carbonizing the carbons.

I produce my carbons in the following manner: I take any suitable vegetable fibers of sufficient length and stretch the same between two pointsfor instance, by suspension at one end and weights at the other, or in any other suitable way by which the fibers may, by tension, be made straight. While in this position I coat such fibers with an even coating of lampblack and varnish, and this latter operation is repeated until the required size or thickness is obtained, when the fibers are dried, either slowly or rapidly, as may be most convenient.

After the fibers thus coated have become thoroughly dried, they will be bound straight and strong, when they should be cut into proper lengths and attached to the platinum conducting-wires a, which pass through the plug b, in the manner well known to electricians.

The means which I employ in fastening the fiber c to the conducting-wires is as follows: I cut sections d, of straw, about a quarter of an inch long, through which the bore is about a thirty-second of an inch inside diameter, which sections I prepare for use by first cutting the tubes of proper length, then drying the same at a temperature of about 300 Fahrenheit, then boil in fatty oil, after which I drain carefully, so that no drops adhere, and then dry.

\Vhen the tubes are perfectly dry, place the same in crucible with carbon dust and bake at a high temperature. After this carbonization, boil the tubes again in fatty oil or other similar material, then drain well, and carbonize again, bringing the whole to as high a temperature as possible. Now the tube or collars will be ready for making connection by sticking them over the adjacent ends of the wires and fiber, and in order-to secure a perfect contact between the ends of the wires and fiber I fill the small space left in the collar with acompound of lamp-black and varnish, which, when dried, will be found to make a solid and continuous connection. I next carbonize the filament and collar by the apparatus shown in the drawings, in which A is an oven provided with a perforated cover, B, as shown in Figs. 2 and 3, and into each of these perforations I drop an iron tube or pot, 0, closed at its lower end, with an enlargement or collar, 6, at its upper end, to prevent the tube from dropping through the cover. I now place the prepared fiber, as described and secured to the wires and plug, into the upper end of the tube, so that the lower end of the glass plug will rest upon or above the diaphragm H, of asbestus, above which I fill the upper end of the tube around the glass plug with ashes, carbon dust, or other suitable material for heating the same, by means of which all atmospheric air is excluded from the retort C. Suitable heat now being applied to the oven will soon carbonize the fiber, the collar, and filling, by means of which said fiber is connected with the wires. The plug, with the fiber, is then removed from the retort, and is ready to be inserted into the mouth or neck of the bulb-such as is ordina rily employed for incandescent lights-the pro jecting platinum wires forming the means of connection with the source of electricity.

I am aware that cane or bamboo collars have been employed, and hence make no claim to such material, as when said materials are of the proper size for thepurpose the hole for the fiber and wires must be drilled, whereas I use a material that requires no drilling. If the collar has to be drilled, it has to be of comparatively large size to admit of drilling, as otherwise it will be liable to split, and then after drilling it has to be trimmed to make it of the proper size, and even with this trimming presence of two witnesses gust, 1885.

naturally hollow material adapt d o receive the wires, fiber, and filling material without preliminary boring, substantiallyas described.

In testimony whereof I afiix my signature, in I 5 CHARLES J. V

Witnesses:

AMOS K. STILES, WM. A. STILEs.

AN DEPOELE.

, this 3d day of Au- 

